The role of interface traps, series resistance and (Ni-doped PVA) interlayer effects on electrical characteristics in Al/p-Si (MS) structures

Abstract

The main point of this article is to examine in detail the effects of interface/surface states (Nss), series resistance (Rs) and (Ni-doped PVA) polymer interlayer on current–voltage (I–V) and frequency dependent capacitance–voltage (C–V) properties at room temperature. Some main diode parameters such as reverse-saturation current (Is), ideality factor (n), barrier height (BH) (= ΦB(I–V)), Rs, and rectification ratio (RR = IF/IR) at ± 3 V were calculated from the linear part of LnI–V plot as 2.14 × 10−9 A, 1.606, 0.750 eV, 30.5 Ω, and 106, respectively. Energy dependent values of Nss were also extracted from the I–V data by considering voltage dependent ΒΗ and n they decrease from mid-gap of Si towards the bottom of valance band (Ev) almost as exponentially. The doping atoms (Na), Fermi energy level (EF), (ΦB(C–V)), and depletion layer width (WD) were also calculated from the reverse bias C−2–V curves as function of frequency. The achievement of obtained results that manufactured (Ni-PVA) interlayer provide better performance in respect of lower values of leakage current, Nss, Rs, and higher values of RR and shunt resistance. The dielectric value of (Ni-PVA) interlayer was found as 1.44 from the interlayer capacitance (Ci = e′eoA/di) even at 20 kHz and this is higher than the dielectric value of SiO2 at 20 kHz. However, this value can be increased by increasing a dopant level of Ni until 5–7%. Therefore, this interlayer can be successfully use an alternative interface layer compared to traditional oxide interlayers.